The error says "Could not get provider type for dimension 29, does not exist" seems to me your player is in a dimension that does not exists (anymore), possibly because it crashed. So now your player is stuck in a non-existing dimension. What you could do is remove the player .dat file (Though this removes the inventory of the player!) and it would port you to spawn or your bed's location I guess.
For single player that file is located in the folder minecraft\saves\%yoursavedgamename%\players\%yourcharactername%.dat
For a server the files are located at minecraft/world/players
Hope this helps.